Mycoplasma hominis is becoming recognized a human pathogen. It can be detected in a variety of body sites and has an impact adult and pediatric populations. Mycoplasma pneumonias is estimated to be responsible for 12 million cases of tracheobronchitis and atypical pneumonia yearly. There are no commercially available direct antigen diagnostic tests. Current methods of identification require cultivation and serological identification which is time consuming and costly. we propose to develop separate ELISAs for detecting specific antigens of M. hominis and M. pneumonia in clinical specimens. Purified specific antigens of M. hominis and M. pneumonias will be used to develop rabbit, antigen specific, polyclonal antisera and a battery of mouse monoclonal antibodies. The optimal combination of capture and primary antibodies and final reagent formulations will be determined by rigorous evaluation using culture grown organisms, spiked specimens and clinical specimens. The final ELISAs will be evaluated clinically: results obtained with the developed assays will be compared to those obtained by current methodologies. The commercial application of rapid direct tests for M. hominis and M. pneumoniae would greatly impact the frequency of diagnosis, the rapidity of diagnosis, and the appropriate treatment of the ill patient.